It is always a hot spot in scientific field to reduce friction and improve anti-wear property since the reduction of friction loss would lead to stronger mechanical power and higher product efficiency. One of important ways for reducing friction loss and increasing product efficiency is to strengthen and rehabilitate the friction surface and worn surface of machine parts. At present, the friction surface of machine parts generally could be strengthened by the following three approaches: 1) strengthening the surface of parts by pre-treatment, including heat treatment strengthening methods such as carburizing, sulfurizing and carbonitriding, film-deposition techniques such as TiN film and DLC film, and mechanical strengthening methods such as shot peening and knurl; 2) surface repairing and regenerating techniques for the worn surface of machine parts, including thermal spraying, brush plating and other surface repairing and regenerating techniques; and 3) in-situ alloying the surfaces of friction pairs by using a lubricant as carrier to convey a formulation with special repairing function into the friction contact regions of machine parts wherein a mechno-chemical reaction (tribo-chemical reaction) among the formulation, the surfaces of friction pairs and third bodies such as wear debris occurs.
The above approaches 1) and 2) are off-line strengthening techniques and have some inherent disadvantages, such as complex procedure, long processing time and high cost. The approach 3) is currently a hot spot in the anti-wear field. However, the currently used products for the approach 3) are not stable in performance and thereby not being widely applied, since the phase structure and mechanical properties of the generated anti-wear layer are still unknown.